For us to have a theory of everything, will we have to study every single inch of the universe? I mean how can we know we have a theory of everything, when we don't know the whole universe. For all we know there could be a different set of laws somewhere else, billions of light years away. Or maybe a pocket somewhere, where particles stop being "rational" and "normal." I mean there are many possibilities, at least now. So my point is, does this mean we can safely say we will never have a theory of everything unless we explore the entire universe? But then again if the universe is expanding at an ever increasing rate, we will never reach the end, as such we would have to assume about what is "out there" where we can't reach. Unless there is a safe way to say like, "we know x1, therefore unknown factor x2 cannot exist." Any comments?